JP2006153696A - Damage measurement method - Google Patents

Damage measurement method Download PDF

Info

Publication number
JP2006153696A
JP2006153696A JP2004345767A JP2004345767A JP2006153696A JP 2006153696 A JP2006153696 A JP 2006153696A JP 2004345767 A JP2004345767 A JP 2004345767A JP 2004345767 A JP2004345767 A JP 2004345767A JP 2006153696 A JP2006153696 A JP 2006153696A
Authority
JP
Japan
Prior art keywords
measured
sample
ratio
phase difference
frequency
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP2004345767A
Other languages
Japanese (ja)
Other versions
JP4517073B2 (en
Inventor
Tetsuo Iwashita
哲雄 岩下
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
National Institute of Advanced Industrial Science and Technology AIST
Original Assignee
National Institute of Advanced Industrial Science and Technology AIST
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by National Institute of Advanced Industrial Science and Technology AIST filed Critical National Institute of Advanced Industrial Science and Technology AIST
Priority to JP2004345767A priority Critical patent/JP4517073B2/en
Publication of JP2006153696A publication Critical patent/JP2006153696A/en
Application granted granted Critical
Publication of JP4517073B2 publication Critical patent/JP4517073B2/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Landscapes

  • Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To provide a damage measurement method for precisely measuring the damage, depletion or the like of a wide range of a conductive composite material containing a fine powdery conductive material. <P>SOLUTION: The damage measurement method is constituted so that a series circuit, wherein a reference sample and a sample to be measured are connected in series, is connected to a frequency variable high-frequency power supply, the admittance values and phases of the reference sample and the sample to be measured are measured while changing the frequency of the power supply, the ratio A of the measured admittance values of both samples and the phase difference B between both samples are calculated, the ratio C of the admittance values of both samples and the phase difference D between both samples in a case that the reference samples are mutually set as measurement targets are calculated in the same way and the deviations of the ratio A of the admittance values and the ratio C of the admittance values are compared to judge the quality of the sample to be measured while the deviations of the phase difference B and the phase difference D are compared to judge the quality of the sample to be measured. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は、各種材料の損傷を電気的に測定する損傷測定方法に関する。   The present invention relates to a damage measuring method for electrically measuring damage of various materials.

固体高分子形燃料電池（ＰＥＦＣ）の基幹部品であるセパレータには、プロトン（Ｈ＋）導伝型の固体高分子膜の場合、セル内の雰囲気は、非常に強い酸性となっているため、セパレータとして使用される材料は制限される。ＰＥＦＣ用セパレータ材料としては、サブミクロンからミクロンオーダーのカーボン（黒鉛）粉末と樹脂の複合材料をプレス成型あるいは射出成型によって作製するカーボン樹脂モールドセパレータが生産されている。このセパレータは、加工が容易で、生産性が高く、大幅なコストダウンを計ることができる。
このセパレータに対し長期間にわたって必要十分な安全性をもたせるため、材料強度に及ぼす環境効果、特に腐食性環境効果の解明ならびに微小な劣化の診断評価方法の確立が望まれている。
カーボン樹脂モールドセパレータのような導電性複合材料（導電材を樹脂結合したもの）の損傷測定方法および装置としては、下記特許文献１に示されるようなものが提案されている。
特許文献１には、プラスチック材の内部に導電性繊維束をプラスチック材と一体に設けた繊維強化プラスチック複合材の抵抗を、導電性繊維束の両端に測定端子を設けて増加抵抗を測定してゆがみ率を求め、その値から複合材料の応力度状態および破壊進行状況を把握する破壊予知方法が示されている。
特開平０５−３３２９６５号公報 In the case of a proton (H + ) conduction type solid polymer membrane, the atmosphere in the cell is very strong acidity in the separator that is a basic part of the polymer electrolyte fuel cell (PEFC). The material used as a separator is limited. As a separator material for PEFC, a carbon resin mold separator is produced in which a composite material of carbon (graphite) powder and resin of submicron to micron order is produced by press molding or injection molding. This separator is easy to process, has high productivity, and can greatly reduce the cost.
In order to provide this separator with necessary and sufficient safety for a long period of time, it is desired to elucidate environmental effects on material strength, particularly corrosive environmental effects, and to establish diagnostic evaluation methods for minute deterioration.
As a damage measuring method and apparatus for a conductive composite material (one obtained by resin-bonding a conductive material) such as a carbon resin mold separator, the one shown in Patent Document 1 below has been proposed.
In Patent Document 1, the resistance of a fiber reinforced plastic composite material in which a conductive fiber bundle is provided integrally with a plastic material inside a plastic material is measured, and the increase resistance is measured by providing measurement terminals at both ends of the conductive fiber bundle. A fracture prediction method is described in which the distortion rate is obtained and the stress state and fracture progress of the composite material are determined from the values.
JP 05-332965 A

前記特許文献１記載の破壊予知方法は、ミクロンオーダーのカーボン（黒鉛）粉末と樹脂の複合材料をプレス成型あるいは射出成型によって作製するカーボン樹脂モールドセパレータ等の導電性複合材料を対象とする破壊予知方法ではなかったので、実際に使用することができなかった。
そこで、交流電流による導電性および位相の周波数依存性が、微小な損傷を検出するための手法として有効であるか検討した。
本発明の目的は、上記問題点に鑑み、微細な粉末の導電材料を含む広範囲の導電性複合材料の傷、欠損等を精度良く測定する損傷測定方法を提供することにある。 The fracture prediction method described in Patent Document 1 is a fracture prediction method for a conductive composite material such as a carbon resin mold separator in which a composite material of micron-order carbon (graphite) powder and resin is produced by press molding or injection molding. Because it was not, it could not be used actually.
Therefore, it was examined whether the electrical conductivity due to alternating current and the frequency dependence of the phase are effective as a technique for detecting minute damage.
In view of the above problems, an object of the present invention is to provide a damage measurement method for accurately measuring scratches, defects, etc. of a wide range of conductive composite materials including fine powder conductive materials.

本発明は課題を解決する手段として以下の手段を採用する。
損傷測定方法として、基準となる試料と被測定試料を直列に接続した直列回路を周波数可変の高周波電源に接続し、該電源の周波数を変えながら前記基準となる試料と前記被測定試料のアドミッタンス値および位相を測定し、その測定した両試料のアドミッタンス値の比Ａおよび位相差Ｂを求め、同じく基準となる試料同士を測定対象とした場合の両試料のアドミッタンス値の比Ｃおよび位相差Ｄを求め、前記アドミッタンス値の比Ａと前記アドミッタンス値の比Ｃの偏差を比較して被測定試料の良否を判断すると共に、前記位相差Ｂと前記位相差Ｄの偏差を比較して被測定試料の良否を判断する測定方法を採用する。 The present invention adopts the following means as means for solving the problems.
As a damage measurement method, a series circuit in which a reference sample and a sample to be measured are connected in series is connected to a frequency variable high frequency power supply, and the admittance value of the reference sample and the sample to be measured is changed while changing the frequency of the power supply. The phase A is measured, the ratio A and the phase difference B of the measured admittance values of both samples are obtained, and the ratio C and the phase difference D of the admittance values of both samples when the reference samples are also measured. And determining the quality of the sample to be measured by comparing the deviation between the ratio A of the admittance value and the ratio C of the admittance value and comparing the deviation between the phase difference B and the phase difference D Use a measurement method to judge pass / fail.

本発明の損傷測定方法は、微細な粉末の導電材料を含む広範囲の導電性複合材料の傷、欠損等を精度良く測定することができる。   The damage measurement method of the present invention can accurately measure scratches, defects, etc. of a wide range of conductive composite materials including fine powder conductive materials.

本願発明の実施例を図に基づいて詳細に説明する。
本発明は、損傷測定方法として、基準となる試料と被測定試料を直列に接続した直列回路を周波数可変の高周波電源に接続し、該電源の周波数を変えながら前記基準となる試料と前記被測定試料のアドミッタンス値および位相を測定し、その測定した両試料のアドミッタンス値の比Ａおよび位相差Ｂを求め、同じく基準となる試料同士を測定対象とした場合の両試料のアドミッタンス値の比Ｃおよび位相差Ｄを求め、前記アドミッタンス値の比Ａと前記アドミッタンス値の比Ｃの偏差を比較して被測定試料の良否を判断すると共に、前記位相差Ｂと前記位相差Ｄの偏差を比較して被測定試料の良否を判断する損傷測定方法に特徴を有する。 Embodiments of the present invention will be described in detail with reference to the drawings.
The present invention provides a damage measurement method in which a series circuit in which a reference sample and a sample to be measured are connected in series is connected to a frequency variable high-frequency power supply, and the reference sample and the measurement target are changed while changing the frequency of the power supply. The admittance value and the phase of the sample are measured, the ratio A and the phase difference B of the measured two samples are obtained, and the ratio C and the admittance value ratio C of both samples when the reference samples are also measured. A phase difference D is obtained, and the deviation of the admittance value ratio A and the admittance value ratio C is compared to judge whether the sample to be measured is good or not, and the phase difference B and the phase difference D are compared. It is characterized by a damage measurement method for judging the quality of a sample to be measured.

（ 交流電流による電気特性の周波数依存性試験 ）
図１は、高周波ＡＣ電源に基準材と供試材を直列に接続した電気特性の周波数依存性測定回路図である。
図１において、高周波ＡＣ電源には、基準材と供試材が直列に接続されている。基準材と供試材には、それぞれ試験装置ＣＨ１、ＣＨ２が接続されている。
供試材の寸法は、３ｘ１０ｘ１５ｍｍとした。試験装置ＣＨ１、ＣＨ２において、試料をセットするために板バネ状の電極をつけた可動ブロックによって試料を挟み込んでジグに固定させた。挟み込む方向は、厚さ３ｍｍのプレス方向と、長さ１５ｍｍのプレス面方向の二方向を測定した。ジグには２つの試料をセットする。高周波ＡＣ電源からの交流電流を基準材と供試材の直列回路に流す。試験装置ＣＨ１、ＣＨ２は、各々の試料両端の導電性と位相を測定するのではなく、基準材と供試材のアドミッタンス値と位相を測定する機能を有する。
周波数アナライザーは、試験装置ＣＨ１およびＣＨ２の間の相対比（レシオ）を測定する機能を有する。
（ 交流電流による電気特性の周波数依存性 ） (Frequency dependence test of electrical characteristics by alternating current)
FIG. 1 is a circuit diagram for measuring the frequency dependence of electrical characteristics in which a reference material and a test material are connected in series to a high-frequency AC power source.
In FIG. 1, a reference material and a test material are connected in series to the high-frequency AC power source. Test devices CH1 and CH2 are connected to the reference material and the test material, respectively.
The dimension of the test material was 3 × 10 × 15 mm. In the test apparatuses CH1 and CH2, in order to set the sample, the sample was sandwiched by a movable block provided with a leaf spring-like electrode and fixed to the jig. The sandwiching direction was measured in two directions: a press direction with a thickness of 3 mm and a press surface direction with a length of 15 mm. Two samples are set on the jig. An alternating current from a high frequency AC power supply is passed through a series circuit of a reference material and a test material. The test apparatuses CH1 and CH2 have a function of measuring the admittance values and phases of the reference material and the test material, instead of measuring the conductivity and phase of both ends of each sample.
The frequency analyzer has a function of measuring a relative ratio (ratio) between the test apparatuses CH1 and CH2.
(Frequency dependence of electrical characteristics due to AC current)

試験装置ＣＨ１とＣＨ２に同種で損傷のないセパレータ材をセットした状態（基準状態を測定する条件）と、試験装置ＣＨ１又はＣＨ２の一方に前記損傷のないセパレータ材をセットし、他方の試験装置に測定対象の損傷したセパレータ材をセットした状態（被測定物を測定する条件）の交流電流による導電性（アドミッタンス値）および位相差の周波数依存性を図２に示す。但し、図２中では、横軸は周波数、縦軸はアドミッタンス値の比（ｄＢ）、位相差（ｄｅｇｒｅｅ）。なお、位相差は図中、縦軸で「位相」と記載されている。
電流はセパレータ材の長さ方向（横方向）に流す。図２の縦軸の導電性（アドミッタンス）の相対比（Ｒａｔｉｏ）はデシベル（ｄＢ）で示した。図２を見てわかるように同種の損傷のない供試材をセットしてそれらの相対比挙動を計測すると導電性および位相差がともにわずかに変動する。これはジグなどの残留成分が検出されたことによる。この残留成分は、周波数アナライザーのチャンネルとジグのセット場所を交換することによって、キャンセルすることが可能である。
例えば表面を損傷したセパレータ材（被測定物）の計測の場合には、導電性（アドミッタンス）レシオ値は変化し、損傷の影響を検出することができる。また、位相差については高周波になると著しく変化していることがわかる。位相が負の方向へシフトすることから、容量リアクタンスの増加に起因すると考えられる。また、８０ｋＨｚ付近に見られる位相差の極小値は、供試材中の容量成分による容量リアクタンスとインダクタンス成分による誘導リアクタンスに関係している。前記両リアクタンスは、電圧や電流の位相と周波数の関数であることから、この極小値の現れる周波数−アドミッタンスレシオ特性上の位置によって導電複合材料中の界面剥離の大きさや量を推定できる。 A state in which separator materials of the same type and without damage are set in the test apparatuses CH1 and CH2 (conditions for measuring the reference state), and the separator material without damage is set in one of the test apparatuses CH1 and CH2, and the other test apparatus is set. FIG. 2 shows the frequency dependence of the electrical conductivity (admittance value) by the alternating current and the phase difference in a state where the damaged separator material to be measured is set (conditions for measuring the object to be measured). However, in FIG. 2, the horizontal axis represents frequency, and the vertical axis represents admittance value ratio (dB) and phase difference (degree). The phase difference is indicated as “phase” on the vertical axis in the figure.
The electric current is passed in the length direction (lateral direction) of the separator material. The relative ratio (Ratio) of conductivity (admittance) on the vertical axis in FIG. 2 is expressed in decibels (dB). As can be seen from FIG. 2, when the same kind of non-damaged specimens are set and their relative ratio behavior is measured, both the conductivity and the phase difference slightly change. This is because residual components such as jigs are detected. This residual component can be canceled by exchanging the setting location of the frequency analyzer channel and jig.
For example, in the case of measuring a separator material (object to be measured) whose surface is damaged, the conductivity (admittance) ratio value changes, and the influence of damage can be detected. It can also be seen that the phase difference changes significantly at higher frequencies. Since the phase shifts in the negative direction, it is considered to be caused by an increase in capacitive reactance. Moreover, the minimum value of the phase difference seen in the vicinity of 80 kHz is related to the capacitive reactance due to the capacitive component and the inductive reactance due to the inductance component in the test material. Since both the reactances are functions of the phase and frequency of voltage and current, the size and amount of interfacial debonding in the conductive composite material can be estimated from the position on the frequency-admittance ratio characteristic where the minimum value appears.

表面をわずかに損傷したことによるアドミッタンスと位相の絶対値の変化は、非常に小さく１００ｋＨｚ程度の周波数帯の装置だけでは、材料中の容量成分やインダクタンス成分を定量的に求めることは困難である。しかしながら、相対的に試料間の差（相対比）を計測することによって損傷を検出することが可能であることがわかった。
（アドミッタンス特性の測定が有効となる理由）
試料の測定されたアドミッタンス特性から、インダクタンスＬ、 容量Ｃ、 抵抗Ｒ の各定数を求める。
試料に高周波電流を流しておき、その電流の周波数を変えていくと、周波数が低い領域で、ほぼ一定となるアドミッタンス値ＹＲが求まる。このアドミッタンス値の逆数は下記数１式の抵抗値Ｒ（Ω）を意味する。
周波数の増加に応じて図３に示すようにアドミッタンスが変化する。 Changes in absolute values of admittance and phase due to slight damage to the surface are very small, and it is difficult to quantitatively determine the capacitance component and the inductance component in the material using only a device in the frequency band of about 100 kHz. However, it was found that damage can be detected by relatively measuring the difference (relative ratio) between samples.
(Reason why measurement of admittance characteristics is effective)
From the measured admittance characteristics of the sample, the constants of inductance L, capacitance C, and resistance R are obtained.
When a high-frequency current is passed through the sample and the frequency of the current is changed, an admittance value Y R that is substantially constant is obtained in a low frequency region. The reciprocal of this admittance value means the resistance value R (Ω) of the following equation (1).
As the frequency increases, the admittance changes as shown in FIG.

図３はアドミッタンス特性と位相特性を示す図である。但し、横軸は周波数、縦軸はアドミッタンス値、位相を表す。図３に示すように、容量成分が有効に作用する周波数が高い領域では、任意の周波数ｆ１（Ｈｚ）でのアドミッタンスをＹｃとすると、以下の数２式の関係が成り立つ。
アドミッタンスがリアクタンスの影響を大きく受ける周波数ｆ（Ｈｚ）付近、換言すると位相特性が ０ ｄｅｇｒｅｅとなる周波数ｆ２（Ｈｚ）付近でのリアクタンス値Ｌ（Ｈ）は、先に求めたＲ， Ｃより以下の数３式のように求めることができる。 FIG. 3 is a diagram showing admittance characteristics and phase characteristics. However, the horizontal axis represents frequency and the vertical axis represents admittance value and phase. As shown in FIG. 3, in the region where the frequency at which the capacitive component effectively acts is high, the relationship expressed by the following formula 2 is established, where Y c is the admittance at an arbitrary frequency f 1 (Hz).
The reactance value L (H) near the frequency f (Hz) at which the admittance is greatly affected by the reactance, in other words, near the frequency f 2 (Hz) where the phase characteristic is 0 degree, is less than the previously obtained R and C. It can be obtained as shown in Equation 3.

図４はセパレータ材の損傷前後における実際のアドミッタンス特性と位相特性を示す図である。横軸は周波数、縦軸はアドミッタンス（Ｓ）と位相（ｄｅｇｒｅｅ）を表す。この周波数範囲では 容量Ｃ および インダクタンスＬ を決定できる周波数 ｆ１および ｆ２ が見出されない。
前記周波数 ｆ１および ｆ２ が見出されない理由は、容量Ｃ およびインダクタンスＬ が非常に小さい値であるためであり、より高い周波数帯が必要である。
そこで、以下説明する両試料のアドミッタンス値の比（レシオ）を求めて、損傷等の影響を測定することに思い至った。
（レシオ測定結果の実例） FIG. 4 is a diagram showing actual admittance characteristics and phase characteristics before and after damage to the separator material. The horizontal axis represents frequency, and the vertical axis represents admittance (S) and phase (degree). In this frequency range, the frequencies f 1 and f 2 that can determine the capacitance C and the inductance L are not found.
The reason why the frequencies f 1 and f 2 are not found is that the capacitance C and the inductance L are very small values, and a higher frequency band is required.
Therefore, the inventors have come up with the idea of measuring the influence of damage and the like by determining the ratio (ratio) of the admittance values of both samples described below.
(Example of ratio measurement result)

カーボン／樹脂モ−ルドプレス材のアドミッタンス測定結果
測定時の測定方向は、横方向がプレス面に垂直方向で、縦方向がプレス面と平行方向とする。
（１） 未処理材と基準となる材料をセットし、未処理材とその基準材とのアドミッタンス値の相対比（レシオ）と位相差を測定すると、試料は双方とも同じ材質なので レシオ（＝２０ｌｏｇ（ＣＨ２／ＣＨ１））は、０（ｄＢ）に近く、位相差においても０ｄｅｇｒｅｅ付近に収まる。高周波領域で若干の誤差が確認されるが、実用上問題とならない。
（２）処理材にキズをつけ、その処理材と基準となる材料との相対比を求める。その場合、高周波になるとアドミッタンス値の比（レシオ）だけでなく、位相差にも顕著な変化が観察される。
この結果から、被測定試料と基準試料のアドミッタンス値の比の特性および位相差の特性を、基準試料同士のアドミッタンス値の比の特性および位相差の特性と比較することにより、被測定試料の良否の判断が可能となる。
The measurement direction when measuring the admittance measurement result of the carbon / resin molded press material is such that the horizontal direction is perpendicular to the press surface and the vertical direction is parallel to the press surface.
(1) Set the untreated material and the reference material, and measure the relative ratio (ratio) and phase difference of the admittance value between the untreated material and the reference material. Since both samples are the same material, the ratio (= 20log) (CH2 / CH1)) is close to 0 (dB), and also falls within the vicinity of 0 degree in phase difference. Although some errors are confirmed in the high frequency region, there is no practical problem.
(2) The processing material is scratched, and the relative ratio between the processing material and the reference material is obtained. In that case, when the frequency becomes high, not only the ratio (ratio) of admittance values but also a significant change is observed in the phase difference.
From this result, comparing the admittance value ratio characteristics and phase difference characteristics of the measured sample and the reference sample with the ratio characteristics and phase difference characteristics of the admittance values between the reference samples, the quality of the measured sample is determined. Can be determined.

高周波ＡＣ電源に基準材と供試材を直列に接続した電気特性の周波数依存性測定回路図である。FIG. 3 is a circuit diagram for measuring frequency dependence of electrical characteristics in which a reference material and a test material are connected in series to a high-frequency AC power source. 試験装置ＣＨ１とＣＨ２に同種のセパレータ材をセットした場合とＣＨ２に損傷したセパレータ材をセットしたときの交流電流による導電性および位相の周波数依存性を示す図である。It is a figure which shows the frequency dependence of the electroconductivity by an alternating current when a separator material of the same kind is set to test apparatus CH1 and CH2, and when a separator material damaged to CH2 is set. アドミッタンス特性と位相特性を示す図である。It is a figure which shows an admittance characteristic and a phase characteristic. セパレータ材の損傷前後における実際のアドミッタンス特性と位相特性を示す図である。It is a figure which shows the actual admittance characteristic and phase characteristic before and after the damage of a separator material.

符号の説明Explanation of symbols

ＣＨ１、ＣＨ２・・試験装置
CH1, CH2 ... Test equipment

Claims (1)

基準となる試料と被測定試料を直列に接続した直列回路を周波数可変の高周波電源に接続し、該電源の周波数を変えながら前記基準となる試料と前記被測定試料のアドミッタンス値および位相を測定し、その測定した両試料のアドミッタンス値の比Ａおよび位相差Ｂを求め、同じく基準となる試料同士を測定対象とした場合の両試料のアドミッタンス値の比Ｃおよび位相差Ｄを求め、前記アドミッタンス値の比Ａと前記アドミッタンス値の比Ｃの偏差を比較して被測定試料の良否を判断すると共に、前記位相差Ｂと前記位相差Ｄの偏差を比較して被測定試料の良否を判断する損傷測定方法。
A series circuit in which a reference sample and a sample to be measured are connected in series is connected to a variable frequency high-frequency power supply, and the admittance value and phase of the reference sample and the sample to be measured are measured while changing the frequency of the power supply. Then, the ratio A and phase difference B of the measured admittance values of both samples are obtained, and the ratio C and phase difference D of the admittance values of both samples when the same reference sample is measured are obtained, and the admittance value The difference between the ratio A and the admittance value ratio C is compared to determine the quality of the measured sample, and the phase difference B and the phase difference D are compared to determine the quality of the measured sample. Measuring method.
JP2004345767A 2004-11-30 2004-11-30 Damage measurement method Expired - Fee Related JP4517073B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2004345767A JP4517073B2 (en) 2004-11-30 2004-11-30 Damage measurement method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2004345767A JP4517073B2 (en) 2004-11-30 2004-11-30 Damage measurement method

Publications (2)

Publication Number Publication Date
JP2006153696A true JP2006153696A (en) 2006-06-15
JP4517073B2 JP4517073B2 (en) 2010-08-04

Family

ID=36632179

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2004345767A Expired - Fee Related JP4517073B2 (en) 2004-11-30 2004-11-30 Damage measurement method

Country Status (1)

Country Link
JP (1) JP4517073B2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011033605A (en) * 2009-08-06 2011-02-17 U-Tec Corp Sensor

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05332965A (en) * 1991-08-15 1993-12-17 Shimizu Corp Fiber-bundle-containing plastic composite material having destruction predicting mechanism and predicting method of destruction of structure using the same
JPH063305A (en) * 1992-06-23 1994-01-11 Mitsubishi Kasei Corp Method for non-destructively inspecting piezo-electric element for micro-crack
JPH1194787A (en) * 1997-07-31 1999-04-09 Era Patents Ltd Measuring apparatus
JP2001242110A (en) * 1999-12-24 2001-09-07 Murata Mfg Co Ltd Testing method for piezoelectric ceramic element

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05332965A (en) * 1991-08-15 1993-12-17 Shimizu Corp Fiber-bundle-containing plastic composite material having destruction predicting mechanism and predicting method of destruction of structure using the same
JPH063305A (en) * 1992-06-23 1994-01-11 Mitsubishi Kasei Corp Method for non-destructively inspecting piezo-electric element for micro-crack
JPH1194787A (en) * 1997-07-31 1999-04-09 Era Patents Ltd Measuring apparatus
JP2001242110A (en) * 1999-12-24 2001-09-07 Murata Mfg Co Ltd Testing method for piezoelectric ceramic element

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011033605A (en) * 2009-08-06 2011-02-17 U-Tec Corp Sensor

Also Published As

Publication number Publication date
JP4517073B2 (en) 2010-08-04

Similar Documents

Publication Publication Date Title
Ekanayake et al. Frequency response of oil impregnated pressboard and paper samples for estimating moisture in transformer insulation
Schilling et al. Analyzing Bending Stresses on Lithium‐Ion Battery Cathodes induced by the Assembly Process
WO2006042000A2 (en) Method and apparatus for electromagnetic-based quality inspection of battery dry electrode structure
Han et al. Interpretation of electrochemical impedance spectroscopy (EIS) circuit model for soils
CN105675657A (en) Skin effect-based sample surface coating nondestructive test method and system
CN103105566A (en) Oil paper insulation electrical equipment aging state detection method based on universal relaxation law
JP2009115747A (en) Method and device for measuring conductive performance of paste
KR101009627B1 (en) Electrical resistance measurement method and component inspection process
CN112485617B (en) Method and device for evaluating insulation aging state of cable
JP4517073B2 (en) Damage measurement method
Koch et al. On-site methods for reliable moisture determination in power transformers
EP3615913B1 (en) Apparatus and method for the non-destructive measurement of hydrogen diffusivity
JP2010160055A (en) Battery inspection method
JP2017015608A (en) Method and apparatus for measuring hardness of steel sheet after hardening treatment
Zhou et al. Frequency-dependence of conductivity of new mineral oil studied by dielectric spectroscopy
JP2008089561A (en) DETECTION METHOD OF INSULATOR DIELECTRIC LOSS ANGLE (CALLED AS tandelta) IN APPARATUS DURING OPERATION
Lee et al. Evaluation of Repeatability for the measurement of DC conductivity of HVDC XLPE model cables
CN215985832U (en) Carbon fiber composite material conductivity measurement system
Korzunin et al. Control of the dielectric properties of a grain oriented electrical steel coating
Zhou et al. Correction of contact free measurement in outdoor insulation diagnostics
Gotoh et al. Measurement of thickness of nickel-layer on steel using electromagnetic method
Robalino et al. A study of oil-paper insulation voltage dependency during frequency response analysis
Hussain et al. Development of a Liquid Silicone Rubber for the application in HVDC Cable Accessories
CN108732210A (en) A kind of piezoelectric device fault of construction detection method based on impedance spectrum
Petersen et al. Integrated thin film Supercapacitor as multifunctional Sensor System

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20070508

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20090902

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20100202

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20100311

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20100406

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20100407

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130528

Year of fee payment: 3

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130528

Year of fee payment: 3

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130528

Year of fee payment: 3

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130528

Year of fee payment: 3

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20140528

Year of fee payment: 4

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

S533 Written request for registration of change of name

Free format text: JAPANESE INTERMEDIATE CODE: R313533

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

LAPS Cancellation because of no payment of annual fees